Influence of image reconstruction parameters on cardiovascular risk reclassification by Computed Tomography Coronary Artery Calcium Score

OBJECTIVE

To investigate the influence of different CT reconstruction parameters on coronary artery calcium scoring (CACS) values and reclassification of predicted cardiovascular (CV) risk.

METHODS

CACS was evaluated in 113 patients undergoing ECG-gated 64-slice CT. Reference CACS protocol included standard kernel filter (B35f) with slice thickness/increment of 3/1.5 mm, and field-of-view (FOV) of 150-180 mm. Influence of different image reconstruction algorithms (reconstructed slice thickness/increment 2.0/1.0-1.5/0.8-3.0/2.0-3.0/3.0 mm; slice kernel B30f-B45f; FOV 200-250 mm) on Agatston score was assessed by Bland-Altman plots and concordance correlation coefficient (CCC) analysis. Classification of CV risk was based on the Mayo Clinic classification.

RESULTS

Different CACS reconstruction parameters showed overall good accuracy and precision when compared with reference protocol. Protocols with larger FOV, thinner slices and sharper kernels were associated with significant CV risk reclassification. Use of kernel B45f showed a moderate positive correlation with reference CACS protocol (Agatston CCC = 0.67), and yielded significantly higher CACS values (p < .05). Reconstruction parameters using B30f or B45f kernels, 250 mm FOV, or slice thickness/increment of 2.0/1.0 mm or 1.5/0.8 mm, were associated with significant reclassification of CV risk (p < .05).

CONCLUSIONS

Kernel, FOV, slice thickness and increment are major determinants of accuracy and precision of CACS measurement. Despite high agreement and overall good correlation of different reconstruction protocols, thinner slices thickness and increment, and sharper kernels were associated with significant upward reclassification of CV risk. Larger FOV determined both upward and downward reclassification of CV risk.

Femoroacetabular impingement: biomechanical and dynamic considerations

Femoroacetabular impingement (F.A.I.) is a pathologic process caused by an abnormal shape of the acetabulum, of the femoral head, or both. F.A.I., often referred to as idiopathic, may be secondary to slipped capital femoral epiphysis, congenital hypoplasia of the femur, Legg-Calvé Perthes disease, post-traumatic mal-union and protrusio acetabuli. From 2009 to 2012 we studied 21 patients (14 males), with a mean age of 52 (33 y - 75 y), affected by idiopathic F.A.I. Every patient underwent pelvic and hip joint X-rays and CT scan with 3D reconstructions, in order to evaluate the morphology of the pelvis and the hip joint and the torsion of the lower limbs (Femoroacetabular ante-retroversion). Our results show an average femoral ante-version angle of 12,4° (15°-20° physiological range) in patients affected by CAM impingement and an average acetabular ante-version angle of 13,5° (15°-20° physiological range) for those with PINCER impingement. These values, in patients affected by F.A.I., are probably related to morphologic and biomechanical features that may lead to the onset of idiopathic femoroacetabular impingement. In the literature, other studies partially support our findings, suggesting a more critical approach to a patient with idiopathic F.A.I. extending evaluations to nearby articulations.

Role of MDCT coronary angiography in the clinical setting: economic implications

PURPOSE

This study evaluated the incremental value and cost-effectiveness ratio of introducing coronary angiography (CA) with multidetector computed tomography (MDCT-CA) in the diagnostic management of patients with suspected coronary artery disease (CAD) compared with the traditional diagnostic workup.

MATERIAL AND METHODS

Five hundred and fifty consecutive patients who underwent MDCT-CA between January 2009 and June 2011 were considered. Patients with atypical chest pain and suspected obstructive CAD were directed to one of two diagnostic pathways: the traditional protocol (examination, stress test, CA) and the current protocol (examination, stress test, MDCT-CA, and CA, if necessary). The costs of each protocol and for the individual method were calculated. Based on the results, the cost-effectiveness ratio of the two diagnostic pathways was compared. A third, modified, diagnostic pathway has been proposed with its relative cost-effectiveness ratio (examination, MDCT-CA, stress test, and CA, if necessary).

RESULTS

Stress test vs. MDCT-CA had an accuracy of 66%, a sensitivity and specificity of 21% and 87%, respectively, and a positive (PPV) and negative (NPV) predictive value of 40% and 70%, respectively. Comparison between conventional CA (CCA) and MDCT-CA showed a sensitivity and specificity of 92% and 89%, respectively, a PPV and NPV of 89%, and an accuracy of 92%. The traditional protocol has higher costs than the second protocol: 1,645 euro against 322 euro (mean), but it shows a better cost-effectiveness ratio. The new proposed protocol has lower costs, mean 261 euro, with a better costeffectiveness ratio than the traditional protocol.

CONCLUSIONS

The diagnostic protocol for patients with suspected CAD has been modified by the introduction of MDCT-CA. Our study confirms the greater diagnostic performance of MDCT-CA compared with stress test and its similar accuracy to CCA. The use of MDCT-CA to select patients for CCA has a favourable cost-effectiveness profile.

Role of coronary angiography MDCT in the clinical setting: changes in diagnostic workup in the real world

PURPOSE

The authors sought to evaluate the incremental value of introducing coronary angiography with multidetector computed tomography (MDCT-CA) compared with the conventional diagnostic workup in managing patients with suspected coronary artery disease (CAD) workup.

MATERIALS AND METHODS

A total of 531 consecutive patients underwent MDCT-CA between April 2008 and August 2010. For each patient the pretest probability of CAD was obtained by using the Morise score as well as the diagnostic performance of the exercise test and of MDCT-CA, considering conventional coronary angiography (CCA) as the gold standard. Based on these results, we calculated the posttest likelihood of CAD after stress testing, comparing the incremental diagnostic value for each category of cardiovascular risk with data obtained with MDCT-CA. The conventional diagnostic workup (without MDCT-CA) was then compared with the modified workup (including MDCT-CA).

RESULTS

The diagnostic performance of the exercise test for identifying patients with significant lesions had a sensitivity and specificity of 20% and 88%, respectively, with positive (PPV) and negative (NPV) predictive value of 41% and 72%, respectively. Taking CA as the gold standard, MDCT-CA had 93% sensitivity, 89% specificity, 88% PPV and 93% NPV compared with CCA in evaluating significant stenoses in the per-patient analysis. The overall diagnostic accuracy of MDCT-CA was 91%. The exercise tests provided no significant incremental diagnostic value compared with cardiovascular history in patients with a low to intermediate risk. Comparison of the diagnostic accuracy of these protocols showed improved performance results for the modified protocol.

CONCLUSIONS

MDCT-CA is the reference modality for the noninvasive exclusion of critical CAD. It provides a very high incremental diagnostic value compared with exercise testing in patients with a low to intermediate risk of CAD. The use of diagnostic protocols based on MDCT-CA ensures improved diagnostic performance compared with those involving conventional exercise electrocardiograms.

Non invasive cardiac vein mapping: role of multislice CT coronary angiography

PURPOSE

Coronary venous anatomy is of primary importance when implanting a cardiac resynchronization therapy device, besides, the coronary sinus can be differently enlarged depending on chronic heart failure. The aim of this study is to evaluate the usefulness of Coronary CTA in describing the coronary venous tree and in particular the coronary sinus and detecting main venous system variants.

MATERIALS AND METHODS

301 consecutive patients (196 ♂, mean age 63.74 years) studied for coronary artery disease with 64 slice Coronary CTA were retrospectively examined. The acquisition protocol was the standard acquisition one used for coronary artery evaluation but the cardiac venous system were visualized. The cardiac venous system was depicted using 3D, MPR, cMPR and MIP post-processing reconstructions on an off-line workstation. For each patient image quality, presence and caliber of the coronary sinus (CS), great cardiac vein (GCV), middle vein (MV), anterior interventricular vein (AIV), lateral cardiac vein (LCV), posterior cardiac vein (PCV), small cardiac vein (SCV) and presence of variant of the normal anatomy were examined and recorded.

RESULTS

CS, GCV, MV and AIV were visualized in 100% of the cases. The LCV was visualized in 255/301 (84%) patients, the PCV in 248/301 (83%) patients and the SCV in 69/301 (23%) patients. Mean diameter of the CS was 8.7 mm in 276/301 (91.7%) patients without chronic heart failure and 9.93 mm in 25/301 (8.3%) patients with chronic heart failure.

CONCLUSIONS

Coronary CTA allows non invasive mapping of the cardiac venous system and may represent a useful presurgical tool for biventricular pacemaker devices implantation.

Classification of noncalcified coronary atherosclerotic plaque components on CT coronary angiography: impact of vascular attenuation and density thresholds

PURPOSE

The authors assessed the effect of vascular attenuation and density thresholds on the classification of noncalcified plaque by computed tomography coronary angiography (CTCA).

MATERIALS AND METHODS

Thirty patients (men 25; age 59 ± 8 years) with stable angina underwent arterial and delayed CTCA. At sites of atherosclerotic plaque, attenuation values (HU) were measured within the coronary lumen, noncalcified and calcified plaque material and the surrounding epicardial fat. Based on the measured CT attenuation values, coronary plaques were classified as lipid rich (attenuation value below the threshold) or fibrous (attenuation value above the threshold) using 30-HU, 50-HU and 70-HU density thresholds.

RESULTS

One hundred and sixty-seven plaques (117 mixed and 50 noncalcified) were detected and assessed. The attenuation values of mixed plaques were higher than those of exclusively noncalcified plaques in both the arterial (148.3 ± 73.1 HU vs. 106.2 ± 57.9 HU) and delayed (111.4 ± 50.5 HU vs. 64.4 ± 43.4 HU) phases (p<0.01). Using a 50-HU threshold, 12 (7.2%) plaques would be classified as lipid rich on arterial scan compared with 28 (17%) on the delayed-phase scan. Reclassification of these 16 (9.6%) plaques from fibrous to lipid rich involved 4/30 (13%) patients.

CONCLUSIONS

Classification of coronary plaques as lipid rich or fibrous based on absolute CT attenuation values is significantly affected by vascular attenuation and density thresholds used for the definition.

Comparison between different kernel reformatting filters in 3D quantitative analysis of MDCT coronary angiography

PURPOSE

Coronary angiography with multidetector-row computed tomography (MDCT-CA) allows quantification of coronary artery stenosis with a high level of accuracy; however, a better estimation of stenosis can be achieved by using appropriate reformatting filters, especially in stents and calcified segments. Quantitative computed tomography angiography (QCTA) is intended to overcome the limitations of the visual score. The aim of this study was to evaluate the accuracy of QCTA with different filters in comparison with quantitative coronary angiography (QCA) and visual score.

MATERIALS AND METHODS

Two blinded operators visually scored 17 consecutive patients referred for MDCT-CA with a per-segment analysis. The degree of stenosis was classified as 0-20%, 20-50% (wall irregularities), 50-70% (significant disease) and 70-100% (vessel occlusion). Each segment was then analysed using the electronic callipers of the QCTA system with 15 different filters. No contour editing was performed. Data were compared with QCA and conventional coronary angiography (CCA). Comparison between QCTA, visual score and QCA were performed using Spearman's rank correlation.

RESULTS

Of 25 segments analysed (mean 1.4 diseased segment per patient), 375 measurements were considered. Good correlation was found between the visual score and QCA [Pearson correlation coefficient (rho=0.852; p<0.0001)] and between QCA and CCA (rho=0.804; p<0.0001). Moderate correlation was found between QCA and QCTA only using two filters (rho=0.444; p<0.0001 for YA filter and rho=0.450; p<0.0001 for YB filter).

CONCLUSIONS

Overall QCTA accuracy is low if contour editing is not applied, especially in calcified vessels. Certain filters can help to better estimate the exact percentage of stenosis.

Computed tomography coronary angiography in asymptomatic patients

PURPOSE

This study assessed the accuracy of computed tomography coronary angiography (CT-CA) for detecting significant coronary artery disease (CAD; ≥50% lumen reduction) in intermediate/high-risk asymptomatic patients.

MATERIALS AND METHODS

A total of 183 consecutive asymptomatic individuals (92 men; mean age 54±11 years) with more than one major risk factor (obesity, hypertension, diabetes, hypercholesterolaemia, family history, smoking) and an inconclusive or nonfeasible noninvasive stress test result (stress electrocardiography, stress echocardiography, nuclear stress scintigraphy) underwent CT-CA in an outpatient setting. All patients underwent conventional coronary angiography (CAG) within 4 weeks. Data from CT-CA were compared with CAG regarding the presence of significant CAD (≥50% lumen reduction).

RESULTS

Mean calcium score was 177±432, mean heart rate during the CT-CA scan was 58±8 bpm and the prevalence (per-patient) of obstructive CAD was 19%. CT-CA showed single-vessel CAD in 9% of patients, two-vessel CAD in 9% and three-vessel CAD in 0%. Per-patient sensitivity, specificity, positive predictive value and negative predictive value of CT-CA were 100% (90-100), 98% (96-99), 97% (85-99), 100% (97-100), respectively. Positive and negative likelihood ratios were 151 and 0, respectively.

CONCLUSIONS

CT-CA is an excellent noninvasive imaging modality for excluding significant CAD in intermediate/ high-risk asymptomatic patients with inconclusive or nonfeasible noninvasive stress test.

Computed tomography coronary angiography in the selection of outlier patients: a feasibility report

PURPOSE

This study evaluated criteria, presence and distribution of outlier patients by means of computed tomography coronary angiography (CTCA) in a large institutional database.

MATERIAL AND METHODS

From a population of 2,881 consecutive patients (1,842 men, mean age 62 ± 13 years) in sinus rhythm who underwent CTCA, we extracted data on patients with suspected coronary artery disease (CAD). We selected patient outliers in the fifth and sixth decades of life with the following criteria: ≥ 3 risk factors and absence of CAD, zero to one risk factors and ≥ 5 diseased coronary segments. Diabetes was excluded from risk factors because of the different impact on CAD.

RESULTS

The patient population consisted of 2,432 individuals with suspected CAD (1,495 men, age 62 ± 13 years). The prevalence of obstructive CAD (≥ 50% lumen reduction at CTCA) was 36% (863/2,432). Patients with normal coronary arteries accounted for 34% of the total (837/2,432; 431 men, age 55 ± 14 years). Of these, 210 were in the fifth and 231 in the 6th decade (men 196, women 245); those with ≥ 3 risk factors accounted for 4.2% of the total (102/2,432; men 42, women 60). Patients with ≥ 5 diseased coronary segments accounted for 28% of the total (686/2,432; 510 men, age 68 ± 10 years). Of these, 115 were in the fifth and 270 in the sixth decade (men 309, women 76); those with zero to one risk factors accounted for 3.0% (73/2,432; men 66, women 7).

CONCLUSIONS

CTCA is a reliable noninvasive diagnostic modality that can be used to identify outlier patients. This will enable dedicated trials aimed at characterising biomarkers and genomics of protective and nonprotective factors against CAD and its complications.

Anatomical variants and anomalies of the coronary tree studied with MDCT coronary angiography

Anomalies of the coronary arteries are congenital and in most of the cases asymptomatic, although they may present with severe symptoms such as angina pectoris or cardiac arrest. Multidetector CT coronary angiography (MDCT-CA) permits, through curved multiplanar reconstructions and three-dimensional reformatting, noninvasive visualisation of the coronary tree and its variants and anomalies, providing a more accurate alternative to conventional coronary angiography (CCA). The purpose of this pictorial essay is to describe the main variants and anomalies of the coronary arteries using MDCT imaging with multiplanar and three-dimensional reconstructions.

Resectable pancreatic adenocarcinoma: is the enhancement pattern at contrast-enhanced ultrasonography a pre-operative prognostic factor?

The aim of our study was to determine whether the enhancement pattern of pancreatic adenocarcinoma at contrast-enhanced ultrasonography (CEUS) is related to patient prognosis after resection. CEUS of 42 resected adenocarcinomas were retrospectively reviewed. Tumors were divided into two groups: group A=poorly vascularized (presence of avascular areas) or group B=well vascularized (absence of avascular areas). All lesions were resected and underwent pathological examination assessing tumor differentiation as: undifferentiated (poorly differentiated) or differentiated (moderately and well differentiated). Mean vascular density (MVD) was also evaluated. CEUS enhancement and pathology were correlated (Spearman's test). Survival was analyzed with the Kaplan-Meier method. Multivariate analysis was performed with the Cox regression model. There were 30 differentiated and 12 undifferentiated adenocarcinomas at pathology. At CEUS, 10 lesions were poorly vascularized, whereas 32 lesions were well vascularized. Positive correlation was observed between CEUS groups and tumoral differentiation (rs=0.51; p=0.001) and between CEUS and MVD (rs=0.74; p<0.0001). Median survival in patients with group A vascularization at CEUS was significantly lower than in group B (p=0.015). Cox proportional hazard model revealed the presence of poorly vascularized tumor at CEUS (p=0.0001) as a predictor of higher mortality. In conclusion, CEUS enables accurate depiction of the vascularization of adenocarcinoma, with positive correlation to histology grade and MVD.

Prevalence of myocardial bridging and correlation with coronary atherosclerosis studied with 64-slice CT coronary angiography

PURPOSE

This study aimed to assess the prevalence and characteristics of myocardial bridging in patients who underwent multislice computed tomography coronary angiography (MSCT-CA) and to evaluate the correlation between bridged coronary segments and atherosclerosis.

MATERIALS AND METHODS

A total of 277 patients (mean age 60+/-11 years) we consecutively examined with 64-slice MSCT-CA for suspected or known coronary atherosclerosis were retrospectively reviewed for myocardial bridging. Segments proximal and distal to the bridging were evaluated for atherosclerotic plaque, as were the remaining coronary segments.

RESULTS

Myocardial bridging was present in 82 patients (30%, mean age 59+/-12). Bridges were of variable length (<1 cm 58%; 1-2 cm 32%; >2 cm 10%) and depth (superficial 69%, intramyocardial 31%) and frequently localised in the mid-distal segment of the left anterior descending artery (95%). Myocardial bridging cannot be considered a significant risk factor for coronary atherosclerosis (odds ratio 0.49) compared with traditional cardiovascular risk factors. Coronary segments proximal to the bridge showed no atherosclerotic disease (33%), positive remodelling (27%), <50% stenosis (20%) or >50% stenosis (20%). We identified 12 noncalcified, 32 mixed and 17 calcified plaques. The distal segments were significantly less affected (p<0.0001).

CONCLUSIONS

MSCT-CA is a reliable, noninvasive method that is able to depict myocardial bridging and associated atherosclerotic plaque in the proximal segments.

Dose reduction in spiral CT coronary angiography with dual-source equipment. Part I. A phantom study applying different prospective tube current modulation algorithms

PURPOSE

The authors sought to compare different algorithms for dose reduction in retrospectively echocardiographically (ECG)-gated dual-source computed tomography (CT) coronary angiography (DSCT-CA) in a phantom model.

MATERIALS AND METHODS

Weighted CT dose index (CTDI) was measured by using an anthropomorphic phantom in spiral cardiac mode (retrospective ECG gating) at five pitch values adapted with two heart-rate-adaptive ECG pulsing windows using four algorithms: narrow pulsing window, with tube current reduction to 20% (A) and 4% (B) of peak current outside the pulsing window; wide pulsing window, with tube current reduction to 20% (C) and 4% (D). Each algorithm was applied at different heart rates (45, 60, 75, 90, 120 bpm).

RESULTS

Mean CTDI volume (CTDIvol) was 36.9+/-9.7 mGy, 23.9+/-5.6 mGy, 49.7+/-16.2 mGy and 38.5+/-12.3 mGy for A, B, C and D, respectively. Consistent dose reduction was observed with protocols applying the 4% tube current reduction (B and D). Using the conversion coefficient for the chest, the mean effective dose was the highest for C (9.6 mSv) and the lowest for B (4.6 mSv). Heart-ratedependent pitch values (pitch=0.2, 0.26, 0.34, 0.43, 0.5) and the use of heart-rate-adaptive ECG pulsing windows provided a significant decrease in the CTDIvol with progressively higher heart rates (45, 60, 75, 90, 120 bpm), despite using wider pulsing windows.

CONCLUSIONS

Radiation exposure with DSCT-CA using a narrow pulsing window significantly decreases when compared with a wider pulsing window. When using a protocol with reduced tube current to 4%, the radiation dose is significantly lower.

Detection of focal liver lesions: from the subjectivity of conventional ultrasound to the objectivity of volume ultrasound

PURPOSE

This study was undertaken to establish the reliability of automated volumetric liver scans in detecting focal liver lesions by evaluating the degree of agreement between conventional and volume ultrasound (US) examinations.

MATERIALS AND METHODS

Over a period of 3 months, we prospectively studied 100 consecutive patients (36 men and 64 women; age range 15-87 years; mean age 63 years) referred to our institute for US imaging of the liver. Volumetric acquisition of the liver was achieved with a 3D transducer (2.0-5.0 MHz) and a Logiq 9 US scanner. All patients underwent both 2- and 3D US studies performed by two expert radiologists. Volumetric acquisitions were subsequently reviewed by the second radiologist, who was blinded to the first radiologist's report. Three categories were established: 1=presence of focal liver lesions; 2=doubtful finding; 3=absence of focal liver lesions. Concordance between volume US and conventional US was calculated by using the k statistic.

RESULTS

Out of 100 patients examined, 39 were found to be affected by focal liver lesions. All volume US examinations were technically adequate, allowing exploration of all hepatic sectors, except for five cases that were marred by major respiratory motion artefacts. Conventional and volume US identified the same number of focal liver lesions, with the exception of four cases of doubtful findings at volume US. Concordance between automated volume US and conventional US of the liver was high (k=0.92).

CONCLUSIONS

The identification of focal liver lesions on automated volume US is possible, and the examination shows a high level of concordance with conventional US.

Computed tomography coronary angiography vs. stress ECG in patients with stable angina

PURPOSE

This study compared the role of multislice computed tomography coronary angiography (MSCT-CA) and stress electrocardiography (ECG) in the diagnostic workup of patients with chronic chest pain.

MATERIALS AND METHODS

MSCT-CA was performed in 43 patients (31 men, 12 women, mean age 58.8+/-7.7 years) with stable angina after a routine diagnostic workup involving stress ECG and conventional CA. The following inclusion criteria were adopted: sinus rhythm and ability to hold breath for 12 s. Beta-blockers were administered in patients with heart rate>or=70 beats/minute. In order to identify or exclude patients with significant stenoses (>or=50% lumen), we determined posttest likelihood ratios of stress test and MSCT-CA separately and of MSCT-CA performed after the stress test.

RESULTS

The pretest probability of significant coronary artery disease (CAD) was 74%. Positive and negative likelihood ratios were 2.3 [95% confidence interval (CI) 1.0-5.3] and 0.3 (95% CI: 0.2-0.7) for the stress test and 10.0 (95% CI: 1.8-78.4) and 0.0 (95% CI: 0.0-infinity) for MSCT-CA, respectively. MSCT-CA increased the posttest probability of significant CAD after a negative stress test from 50% to 86% and after a positive stress test from 88% to 100%. MSCT-CA correctly detected all patients without CAD.

CONCLUSIONS

Noninvasive MSCT-CA is a potentially useful tool in the diagnostic workup of patients with stable angina owing to its capability to detect or exclude significant CAD.

Prevalence and characteristics of coronary artery disease in a population with suspected ischemic heart disease using CT coronary angiography: correlations with cardiovascular risk factors and clinical presentation

PURPOSE

This study was undertaken to describe the correlation between the distribution of coronary artery disease (CAD) in a symptomatic population with suspected ischaemic heart disease, cardiovascular risk factors (RF) and clinical presentation.

MATERIALS AND METHODS

we studied 163 patients (mean age 65.5 years; 101 men and 62 women) referred for multidetector computed tomography coronary angiography (MDCT-CA) to rule out CAD. The patients had no prior history of revascularisation or myocardial infarction. We analysed how the characteristics of CAD (severity and type of plaque) can change with the increase in RF and how they are related to different clinical presentations.

RESULTS

patients were divided into three groups according to the number of RF: zero or one, two or three, and four or more. The percentage of coronary arteries with no plaque, nonsignificant disease and significant disease was 55%, 41% and 4%, respectively, in patients with zero or one RF; 27%, 51% and 22%, respectively, in patients with two or three RF; and 19%, 38% and 44%, respectively, in patients with four or more RF. Plaque in patients with nonsignificant disease was mixed in 65%, soft in 18% and calcified in 17%. The percentage of coronaries with no plaque in the three RF groups was 50%, 20% and 0% in patients with typical chest pain and 46%, 24% and 12% in those with atypical pain. The percentage of significant disease in patients with typical pain was 0%, 47% and 86% and in those with atypical pain 4%, 20% and 29%.

CONCLUSIONS

MDCT plays an important role in the identification of CAD in patients with suspected ischaemic heart disease. Severity and type of disease is highly correlated with RF number and assumes different characteristics according to clinical presentation.

Fibromuscular dysplasia: noninvasive evaluation of unusual case of renal and mesenteric involvement

Fibromuscular dysplasia is the most common cause of renovascular hypertension in young patients. It primarily involves the renal and carotid arteries, and it is less common in the coronary, iliac, and visceral arteries. Digital subtraction angiography is still the best investigation to determine the location, extent, and complications of renal artery involvement. However, currently, other imaging modalities such as ultrasonography, computed tomography, and magnetic resonance imaging can reveal these findings noninvasively. We present the case of a 43-year-old woman who presented with high blood pressure and headache. Imaging revealed fibromuscular dysplasia of the renal arteries and the superior mesentery artery.

Prevalence of anatomical variants and coronary anomalies in 543 consecutive patients studied with 64-slice CT coronary angiography

The aim of our study was to assess the prevalence of variants and anomalies of the coronary artery tree in patients who underwent 64-slice computed tomography coronary angiography (CT-CA) for suspected or known coronary artery disease. A total of 543 patients (389 male, mean age 60.5 ± 10.9) were reviewed for coronary artery variants and anomalies including post-processing tools. The majority of segments were identified according to the American Heart Association scheme. The coronary dominance pattern results were: right, 86.6%; left, 9.2%; balanced, 4.2%. The left main coronary artery had a mean length of 112 ± 55 mm. The intermediate branch was present in the 21.9%. A variable number of diagonals (one, 25%; two, 49.7%; more than two, 24%; none, 1.3%) and marginals (one, 35.2%; two, 46.2%; more than two, 18%; none, 0.6%) was visualized. Furthermore, CT-CA may visualize smaller branches such as the conus branch artery (98%), the sinus node artery (91.6%), and the septal branches (93%). Single or associated coronary anomalies occurred in 18.4% of the patients, with the following distribution: 43 anomalies of origin and course, 68 intrinsic anomalies (59 myocardial bridging, nine aneurisms), three fistulas. In conclusion, 64-slice CT-CA provides optimal visualization of the variable and complex anatomy of coronary arteries because of the improved isotropic spatial resolution and flexible post-processing tool.

Standardize and compare contrast-enhanced ultrasonographic digital images obtained with different technologies: how to overcome the subjectivity

OBJECTIVE

This study was conducted to compare digital images obtained with cadence contrast pulse sequencing (CPS) and coherent contrast imaging (CCI) technologies for contrast-enhanced ultrasonography (CEUS).

METHODS

A CEUS study on 17 focal liver lesions was performed using CPS and CCI technologies with a second-generation contrast media. The lesion/liver ratio and conspicuity index were then calculated and compared with Adobe Photoshop 6.0.

RESULTS

Lesion/liver ratio and conspicuity index using CCI ranged from 1.3 to 7.1 (mean value, 3) and 19 to 127 (mean value, 58), respectively; by using CPS, we obtained results ranging from 2 to 19.1 (mean value, 8.9) and 57 to 164 (mean value, 109.2). Lesion/liver ratio and the conspicuity index for the lesions using CPS showed significantly (p < 0.0001) superior results than those obtained using CCI.

CONCLUSION

The computed analysis with standardization allows an objective evaluation of digital images of CEUS. CPS technology resulted in better lesion conspicuity compared to CCI during CEUS study on focal liver lesions.

Coronary variants and anomalies: methodology of visualisation with 64-slice CT and prevalence in 202 consecutive patients

PURPOSE

This paper aims to provide the tools for a complete anatomical evaluation of the coronary tree using 64-slice computed tomography (CT) and evaluate the prevalence of anatomical variants and anomalies in a population of 202 consecutive patients.

MATERIALS AND METHODS

Two hundred and two patients with suspected coronary artery disease underwent 64-slice CT with a standard protocol. Two observers working in consensus evaluated and collected the data regarding anatomical variants and anomalies of the coronary vessels.

RESULTS

In the 202 consecutive patients, the prevalence of anatomical variants was: left dominant circulation (7%), absent left main (5%), presence of intermediate branch (17%), aortic origin of conus branch (13%) and circumflex origin of sinus node branch (15%). Coronary anomalies (origin and course, intrinsic and termination) showed an overall prevalence of 25%.

CONCLUSIONS

CT is the ideal method for the three-dimensional evaluation of the coronary tree. Anatomical variants and anomalies of the coronary arteries are quite common and should be known and recognised promptly by the operators.

Ultrasonography of the pancreas. 3. Doppler imaging

Ultrasonography is probably the most widely used medical imaging technique. In fact, its non-invasivity, portability, widespread distribution and good clinical results have made it the preferred method for a first imaging approach to patients in a large variety of clinical settings. Ultrasound technology is advancing rapidly, aimed to increase image quality. In particular, increased color-Doppler sensitivity is contributing to the diagnosis and staging of pancreatic disease. Doppler studies are in fact integral part of ultrasound examination of the pancreas evaluating the peripancreatic vascular structures enclose portal vein, splenic artery and vein, superior mesenteric artery and vein, aorta, and inferior vena cava. While flows in all peri-pancreatic vessels are well recognized, only few parenchymal vessels are usually appreciable in normal conditions. Anyway the increased Doppler sensitivity allows the visualization of smaller peri-pancreatic and intra-pancreatic vessels. This article will review the technical background underlying the clinical application of Doppler ultrasonography in pancreatic imaging, with particular emphasis to normal vascular anatomy of the pancreas, and to the main applications of Doppler techniques in the different pancreatic pathologies.

Imaging techniques for the vulnerable coronary plaque

The goal of this article is to illustrate the main invasive and noninvasive diagnostic modalities to image the vulnerable coronary plaque, which is responsible for acute coronary syndrome. The main epidemiologic and histological issues are briefly discussed in order to provide an adequate background. Comprehensive coronary atherosclerosis imaging should involve visualization of the entire coronary artery tree and plaque characterization, including three-dimensional morphology, relationship with the lumen, composition, vascular remodelling and presence of inflammation. No single technique provides such a comprehensive description, and no available modality extensively identifies the vulnerable plaque. In particular, we describe multislice computed tomography, which at present seems to be the most promising noninvasive tool for an exhaustive image-based quantification of coronary atherosclerosis.

Normal pituitary volumes in chronic schizophrenia

Pituitary volumes were shown to be abnormally large in pre- or first-psychotic episode patients and abnormally reduced in established schizophrenia by magnetic resonance imaging (MRI) studies. We present here the results of the second ever published MRI study exploring pituitary size in a large population of patients with chronic schizophrenia recruited from the geographically defined catchment area of South Verona, Italy. No significant differences for pituitary volumes were reported between 65 subjects with chronic schizophrenia and 65 normal individuals (mean age+/-S.D.=42.31+/-11.44 and 40.54+/-11.12 years). In contrast to Pariante et al. (2004), normal pituitary size was found in our population of chronic schizophrenia. Discrepancies between these two studies may partially be accounted by sample age and gender. Considering increased pituitary volumes in pre- or first-psychotic episode patients, we put forward the hypothesis that pituitary size may normalize or reduce with the progression of the illness as a result of reduced numbers of acute episodes and consequent diminished hypothalamus-pituitary-adrenal axis activity. To better test this hypothesis, future large MRI studies should investigate pituitary volumes in chronic schizophrenia longitudinally, also collecting pituitary hormones and cortisol, and comparing the effects of typical and atypical antipsychotics on pituitary size in a randomized trial.

Focal breast lesions with benign appearances. Review of eight breast cancers with initial features of intramammary lymph node

PURPOSE

The aim of this study was to evaluate whether certain histological types of early breast cancer may share radiographic features with intramammary lymph nodes.

MATERIALS AND METHODS

The previous mammograms of patients with histologically proven breast cancer and lesions displaying the morphological features of intramammary lymph nodes were retrospectively reviewed.

RESULTS

Retrospective evaluation demonstrated eight breast cancers of varying histological nature--mostly ductal carcinomas not otherwise specified (NOS)--whose early radiographic features were similar to intramammary lymph nodes.

CONCLUSIONS

Although uncommon, a lesion with the radiographic features of an intramammary lymph node may hide an early breast cancer. No significant relationship exists between histological type and the presence of such features.

Ultrasonography of the pancreas. 5. Interventional procedures

Interventional ultrasonography (US) is often used for the diagnosis and therapy of pancreatic pathologies, and its diffusion has definitely modified the diagnostic and therapeutic management of some diseases. US is particularly suitable for targeting percutaneous pancreatic interventional procedures and important technical features contribute to this result. First of all, US is dynamic, and thus the ongoing procedure can be continually monitored. Then, the high spatial resolution achieved by US imaging in recent years, its speed and availability and the low-cost of the technique, together with the technical features, have led to an ever-increasing use of US in pancreatic interventional procedures. This article will review the application of US as guide of diagnostic and interventional procedures in the different pancreatic pathologies.

Focal liver lesions: sinusoidal phase of CEUS

Ultrasound examination is the first imaging modality for hepatic study in neoplastic and chronic liver diseases. Focal liver lesions frequently cause diagnostic problems in terms of characterization, especially when small and hypoechoic to the rest of the parenchyma. Contrast--enhanced ultrasonography (CEUS) has shown its value in the characterization of focal liver lesions. This study assessed the value of the sinusoidal phase of CEUS with a second-generation contrast agent in the characterization of focal liver lesions to distinguish benign from malignant. Two hundred hepatic lesions with suspicious features at baseline ultrasound were prospectively studied with CEUS. Sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy of the sinusoidal phase in the characterization of benign versus malignant liver lesions were evaluated. Hypoechogenicity of the focal liver lesion, during the sinusoidal phase of CEUS, allowed the diagnosis of malignancy with a sensitivity of 85%, specificity of 88%, positive predictive value of 92%, negative predictive value of 77%, and diagnostic accuracy of 86%. The diagnostic confidence in the diagnosis of malignancy significantly increased, with receiver operating characteristic curve areas from 0.536 for baseline ultrasound to 0.902 for the sinusoidal phase of CEUS.

Imaging of the male breast

Very few studies have dealt with the male breast, in particular as compared with the female breast, no doubt as a result of the high incidence and mortality of breast cancer in women. However, in routine practice breast radiologists are often faced with male breast disorders, but often have difficulties because of the limited experience in this field. The purpose of this pictorial essay is to summarise the clinical, pathophysiological, radiological and ultrasonographic patterns of male breast disorders based on a review of personal cases (398 cases from 1993 to 2004), in an attempt to propose guidelines for a more consistent approach to this only apparently marginal branch of male pathology.

Contrast-enhanced ultrasonography of small solid pseudopapillary tumors of the pancreas: enhancement pattern and pathologic correlation of 2 cases

OBJECTIVE

The purpose of this series is to describe the value of contrast-enhanced ultrasonography (CEUS) in the characterization of small pseudopapillary tumors (SPTs) of the pancreas.

METHODS

Two cases of SPTs found on conventional ultrasonography, both located at the pancreatic body, were studied with spiral computed tomography, magnetic resonance imaging, and CEUS. A final diagnosis was obtained with histologic analysis after distal pancreatectomy. Immunohistochemical analysis of the tumors with the CD34 antigen was performed.

RESULTS

At CEUS, the 2 SPTs had a slight peripheral rim enhancement in the early dynamic phases. The presence of this enhancement pattern at CEUS, not clear at spiral computed tomography or at magnetic resonance imaging, suggested the diagnosis of SPTs with a peripheral pseudocapsule deriving from the compression of the pancreatic parenchyma. The presence of a perilesional pseudocapsule was proved at immunohistochemical analysis of the tumors with the CD34 antigen.

CONCLUSIONS

Contrast-enhanced ultrasonography can improve the characterization of SPTs by showing the typical rim enhancement of these pancreatic tumors.

Hypoechoic focal liver lesions: characterization with contrast enhanced ultrasonography

PURPOSE

To evaluate the late sinusoidal phase of contrast enhancement with a 2nd-generation ultrasound contrast enhanced medium in the characterization of hypoechoic focal liver lesions.

METHODS

We studied 88 hypoechoic liver lesions (diameter range, 1-18 cm; with 18 lesions 2 cm or less) found on conventional grayscale sonography (US) with contrast-enhanced ultrasonography (CEUS). Final diagnosis was made using contrast enhanced helical CT, contrast enhanced MR, angiography (DSA), and/or histopathic confirmation or clinical imaging follow-up.

RESULTS

There were 37/88 benign lesions demonstrated: 17 cavernous hemangiomas, 3 capillary hemangiomas, 11 focal nodular hyperplasias (FNH), 3 focal areas of sparing in hepatic steatosis, 2 adenomas, and 1 intrahepatic necrotic area. Malignant lesions demonstrated included 51/88: 27 hepatocellular carcinomas (HCC) in cirrhosis, 11 metastatic carcinomas, 10 metastatic endocrine tumors, 2 cholangiocellular carcinomas (CCC) and 1 non-Hodgkin's lymphoma (NHL). CEUS characterized 30/37 (81%) benign lesions and 45/51 (88%) malignant lesions. On the basis of the results obtained during the sinusoidal contrast enhanced phase of CEUS, diagnosis of benignancy was possible in 35/37 (95%) of benign liver lesions and diagnosis of malignancy in 49/51 (96%) of malignant liver lesions. The enhancement pattern of 13 small (< or = 2 cm in diameter) hypervascular liver lesions (3 capillary hemangiomas, 2 FNHs, 4 HCCs, 4 metastatic endocrine tumors) was better demonstrated on CEUS than on helical CT. In these cases the hyper vascularization of the lesions shown on CEUS was not confirmed on CT.

CONCLUSIONS

CEUS distinguished malignant from benign hypoechoic liver lesions with an accuracy of 95%.

Contrast-enhanced ultrasonography better identifies pancreatic tumor vascularization than helical CT

BACKGROUND

Contrast-enhanced ultrasonography (CEUS) is a recently introduced field of ultrasonography (US). To assess the ability of CEUS to identify the vascularization of solid pancreatic tumors in comparison to helical CT.

METHODS

Forty-two resected pancreatic tumors, found at US, were studied with CEUS and helical CT. The tumor enhancement at CEUS was scored in comparison to the baseline aspect of the lesion and/or the extralesional pancreatic parenchyma together with the adjacent vessels during the dynamic study. All the lesions underwent pathological examination using H&E stains and CD34 markers with an evaluation of the microvessel density (MVD). The correlation of CEUS and helical CT with the MVD of the lesions was established with Spearman's test.

RESULTS

The correlation of CEUS with the MVD of the lesions was significantly superior (Rs = 0.914; p < 0.0001) to that of helical CT (Rs = 0.635; p < 0.0001).

CONCLUSIONS

CEUS is better than helical CT in the identification of the vascularization of solid pancreatic tumors. CEUS, when the pancreatic gland is optimally visualized, should be therefore considered a complementary imaging modality in the characterization of pancreatic tumors. CEUS can be a valid onco-imaging modality for quantifying tumoral vascularization in a noninvasive and accurate way.

Thymic Masses of the Middle Mediastinum

Although thymic lesions are relatively common causes of anterior mediastinal masses, they can rarely arise in other mediastinal compartments, as it is well recognized that thymic tissue can lie in ectopic intrathoracic locations. A thymic mass within the middle mediastinum has rarely been reported, with only a single case of a thymic cyst described and no reports of a middle mediastinal thymoma. We report 2 thymic masses (1 thymoma and 1 thymic cyst) found to arise in the middle mediastinum.